Track insulation



L. W. TARR TRACK INSULATION Filed Feb. 25, 1929 l Q o y ATTORNEY Ihre/1 for wf/ Patented May 13, 1930 UNITED STATES LESTER W. TARR, OF NEWARK, EELAVJARE, ASSIGNOR, BY MESNE ASSG CONTINENTAL-DIAMOND FIBRE COMPANY, OF HEY. ERK,

TION OF DELAWARE VIEHTS, TO DELLNARE, A CORTEOl- TRACK ELNSZATON Application led February 23, 1929.

This invention relates to an improvement in track insulation.

Vulcanized libre has been used Very largely tor insulation in the case of railway signal systems. lt is a tough material which tullills certain requirements but it is not sa 'istactory because ot the troubles which occur lfrom the libre becoming Wet under atmosphe ic conditions, which renders it a conductor of electric current instead ol" an insulator.

To overcome this dilliculty the present invention utilizes a material for track insulation that Will not absorb moisture appreciably when it becomes Wet and which therefore i5 cannot act as a conductor under such conditions. This material may be a laminated librous material, Which is completely saturated throughout with a phenolic condensation product, such as balrelite, Which product saturates all of the libres of the material so that there could be no possibilty of the absorption of moisture in appreciable quantities, and therefore no possibilty of lessening the insulating qualities of the material when it be- ?f comes Wet.

The material may be used alone or combined With vulcanized libre. lts combination with vulcanized libre strengthens and toughons the insulation considerably, thereby7 pre- ?fi: venting it troni becoming still' ri'l subject to lracture. rl`liis combination is el ected preterably in layers secured together in a suitable manner and shaped to form the desired t ack insulation.

J In the accompanying drawings:

Fig. l is a sectional view through a portion ol a railway rail with the insulation applied thereto;

Fig` 2 is a sectional view through a modili- 4.-@ tion et the arrangemnt oi materials in the insulation Fig. 3 is a. similar view showing a further modilication; and

Fig. 4.- is a perspective View of the insulafl tion.

The numeral l designates the rail, on one or both sides of which the insulation is to be applied. The insulation is designated 0renerally by the numeral 2 and is adapted to be ff: secured to the web portion of the rail Where Serial N0. 342,273.

tion is illu.A rated as being ot three layers, although it may be oi y two it desired, the layers being placed race to face and secured togot ier by cenienting by balrelite ass or some other satisfactory adherl`liis maybe accomplished during ing operation il desired. .ayer-s might also be riveted 'e sides ot vulcanized n the elo to form a sheet from is mol/.led or otherwise termed the proper shape of the track in ulation- This insulating material suitable libre. such as paper or anvas, completely saturated throughout With a phenolic condensation ro duct. such as ba relite, which extends to all of the libres ol the material in or'ler that they will be completely saturated an to prevent any appreciable absorption oi moisture, Which might possibly act to turn the material into a conductor instead of an insulator, Which is very objectionable and undesirable.

The vulcanized liber is a tough material and used to prevent trac-ture of the insulating material.

ln Fig. Q, the vulcanized fibre or toughening material is located on opposite sides ol the iiisulating` librous material, which is the reverse of the arrrangement shown in Fig. l. ln Fig. 3, the insulating material is shovvn on the inside With the vulcanized libre outside, or this arrangement may be reversed in the two-ply material, which is illustrated in Fig. 3. The insulation may be either of two or three-ply and the insulating material. may be either inside or outside ot' the vulcanized libre but these are secured together as a unit. The insulating material serves to insulate the rails effectively While the vulcanized libre that is used in connection therewith acts to overcome the brittleness that may be characteristic ol' some o' the insulating material, rendering it free from fracture.

The insulating material used is of any suitable fibrous nature, such as canvas or paper or other similar material thatl is completely saturated throughout with a phenolic condensation product, such as balelite, Which saturates all of the fibres of the material, renderino` them impervious to moisture, preventing the absorption of moisture and rendering; 'the insulation free from any conducting properties, even under extremely Wet atmospheric conditions.

l claim:

l. A rail insulation formed of fibrous material saturated with a phenolic condensation product, and a fibrous insulating backing material secured thereto.

2. A rail insulation comprising a layer of fibrous material saturated throughout With a phenolic condensation product, and a layer of fibrous insulating backing material integrally secured thereto to prevent fracture of the insulating' material.

3. A rail insulation comprising,` a layer of fibrous insulating material having all of the fibres thereof completely saturated With a phenolicy condensation product, and a layer of vulcanized fibrous material secured to a face thereof to prevent fracture of the insulating material.

4. A rail insulation comprising a layer of fibrous insulating; material saturated throughout with a phenolic condensation product, and a layer of vulcanized fibrous material permanently attached to the surface thereof to strene'then said insulating material.

5. A rail insulation comprising a layer of fibrous insulation material having all of the fibres thereof completely saturated with a phenolic condensation product, and a layer of vulcanized brous material per manentlv attached to the surface thereof as a unit to strengthen said insulating material.

ln testimony whereof I affix my signature.

LESTER Vif. TARE. 

